From edcaa47958c7438b56fc528d4e242f16a249003f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 8 Feb 2021 21:08:59 +0100 Subject: [PATCH] perf daemon: Add 'ping' command Add a 'ping' command to verify that the 'perf record' session is up and operational. It's used in the following patches via test code to make sure 'perf record' is ready to receive signals. Example: # cat ~/.perfconfig [daemon] base=/opt/perfdata [session-cycles] run = -m 10M -e cycles --overwrite --switch-output -a [session-sched] run = -m 20M -e sched:* --overwrite --switch-output -a Start the daemon: # perf daemon start Ping all sessions: # perf daemon ping OK cycles OK sched Ping specific session: # perf daemon ping --session sched OK sched Committer notes: Fixed up bug pointed by clang: Buggy: if (!pollfd.revents & POLLIN) Correct code: if (!(pollfd.revents & POLLIN)) clang warning: builtin-daemon.c:560:6: error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses] if (!pollfd.revents & POLLIN) { ^ ~ builtin-daemon.c:560:6: note: add parentheses after the '!' to evaluate the bitwise operator first Also use designated initialized with pollfd, i.e.: struct pollfd pollfd = { .events = POLLIN, }; Instead of: struct pollfd pollfd = { 0, }; To get past: builtin-daemon.c:510:30: error: missing field 'events' initializer [-Werror,-Wmissing-field-initializers] struct pollfd pollfd = { 0, }; ^ 1 error generated. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Alexei Budankov Cc: Ian Rogers Cc: Ingo Molnar Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20210208200908.1019149-16-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-daemon.txt | 9 ++ tools/perf/builtin-daemon.c | 148 +++++++++++++++++++++++++++++++ 2 files changed, 157 insertions(+) diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt index b1acd46..90b20be 100644 --- a/tools/perf/Documentation/perf-daemon.txt +++ b/tools/perf/Documentation/perf-daemon.txt @@ -15,6 +15,7 @@ SYNOPSIS 'perf daemon start' [] 'perf daemon stop' [] 'perf daemon signal' [] +'perf daemon ping' [] DESCRIPTION @@ -80,6 +81,14 @@ The signal command sends signal to configured sessions. Send signal to specific session. +PING COMMAND +------------ +The ping command sends control ping to configured sessions. + +--session:: + Send ping to specific session. + + CONFIG FILE ----------- The daemon is configured within standard perf config file by diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c index 2c5e68b..fac8605 100644 --- a/tools/perf/builtin-daemon.c +++ b/tools/perf/builtin-daemon.c @@ -499,6 +499,77 @@ static int daemon__wait(struct daemon *daemon, int secs) return 0; } +static int daemon_session__control(struct daemon_session *session, + const char *msg, bool do_ack) +{ + struct pollfd pollfd = { .events = POLLIN, }; + char control_path[PATH_MAX]; + char ack_path[PATH_MAX]; + int control, ack = -1, len; + char buf[20]; + int ret = -1; + ssize_t err; + + /* open the control file */ + scnprintf(control_path, sizeof(control_path), "%s/%s", + session->base, SESSION_CONTROL); + + control = open(control_path, O_WRONLY|O_NONBLOCK); + if (!control) + return -1; + + if (do_ack) { + /* open the ack file */ + scnprintf(ack_path, sizeof(ack_path), "%s/%s", + session->base, SESSION_ACK); + + ack = open(ack_path, O_RDONLY, O_NONBLOCK); + if (!ack) { + close(control); + return -1; + } + } + + /* write the command */ + len = strlen(msg); + + err = writen(control, msg, len); + if (err != len) { + pr_err("failed: write to control pipe: %d (%s)\n", + errno, control_path); + goto out; + } + + if (!do_ack) + goto out; + + /* wait for an ack */ + pollfd.fd = ack; + + if (!poll(&pollfd, 1, 2000)) { + pr_err("failed: control ack timeout\n"); + goto out; + } + + if (!(pollfd.revents & POLLIN)) { + pr_err("failed: did not received an ack\n"); + goto out; + } + + err = read(ack, buf, sizeof(buf)); + if (err > 0) + ret = strcmp(buf, "ack\n"); + else + perror("failed: read ack %d\n"); + +out: + if (ack != -1) + close(ack); + + close(control); + return ret; +} + static int setup_server_socket(struct daemon *daemon) { struct sockaddr_un addr; @@ -549,6 +620,7 @@ enum { CMD_LIST = 0, CMD_SIGNAL = 1, CMD_STOP = 2, + CMD_PING = 3, CMD_MAX, }; @@ -570,8 +642,25 @@ union cmd { int sig; char name[SESSION_MAX]; } signal; + + /* CMD_PING */ + struct { + int cmd; + char name[SESSION_MAX]; + } ping; +}; + +enum { + PING_OK = 0, + PING_FAIL = 1, + PING_MAX, }; +static int daemon_session__ping(struct daemon_session *session) +{ + return daemon_session__control(session, "ping", true) ? PING_FAIL : PING_OK; +} + static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out) { char csv_sep = cmd->list.csv_sep; @@ -668,6 +757,34 @@ static int cmd_session_kill(struct daemon *daemon, union cmd *cmd, FILE *out) return 0; } +static const char *ping_str[PING_MAX] = { + [PING_OK] = "OK", + [PING_FAIL] = "FAIL", +}; + +static int cmd_session_ping(struct daemon *daemon, union cmd *cmd, FILE *out) +{ + struct daemon_session *session; + bool all = false, found = false; + + all = !strcmp(cmd->ping.name, "all"); + + list_for_each_entry(session, &daemon->sessions, list) { + if (all || !strcmp(cmd->ping.name, session->name)) { + int state = daemon_session__ping(session); + + fprintf(out, "%-4s %s\n", ping_str[state], session->name); + found = true; + } + } + + if (!found && !all) { + fprintf(out, "%-4s %s (not found)\n", + ping_str[PING_FAIL], cmd->ping.name); + } + return 0; +} + static int handle_server_socket(struct daemon *daemon, int sock_fd) { int ret = -1, fd; @@ -703,6 +820,9 @@ static int handle_server_socket(struct daemon *daemon, int sock_fd) ret = 0; pr_debug("perf daemon is exciting\n"); break; + case CMD_PING: + ret = cmd_session_ping(daemon, &cmd, out); + break; default: break; } @@ -1138,6 +1258,7 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], signal(SIGINT, sig_handler); signal(SIGTERM, sig_handler); + signal(SIGPIPE, SIG_IGN); while (!done && !err) { err = daemon__reconfig(daemon); @@ -1277,6 +1398,31 @@ static int __cmd_stop(struct daemon *daemon, struct option parent_options[], return send_cmd(daemon, &cmd); } +static int __cmd_ping(struct daemon *daemon, struct option parent_options[], + int argc, const char **argv) +{ + const char *name = "all"; + struct option ping_options[] = { + OPT_STRING(0, "session", &name, "session", + "Ping to specific session"), + OPT_PARENT(parent_options), + OPT_END() + }; + union cmd cmd = { .cmd = CMD_PING, }; + + argc = parse_options(argc, argv, ping_options, daemon_usage, 0); + if (argc) + usage_with_options(daemon_usage, ping_options); + + if (setup_config(daemon)) { + pr_err("failed: config not found\n"); + return -1; + } + + scnprintf(cmd.ping.name, sizeof(cmd.ping.name), "%s", name); + return send_cmd(daemon, &cmd); +} + int cmd_daemon(int argc, const char **argv) { struct option daemon_options[] = { @@ -1303,6 +1449,8 @@ int cmd_daemon(int argc, const char **argv) return __cmd_signal(&__daemon, daemon_options, argc, argv); else if (!strcmp(argv[0], "stop")) return __cmd_stop(&__daemon, daemon_options, argc, argv); + else if (!strcmp(argv[0], "ping")) + return __cmd_ping(&__daemon, daemon_options, argc, argv); pr_err("failed: unknown command '%s'\n", argv[0]); return -1; -- 2.7.4